A tool spindle of this type for a honing machine has become known, for example, through the company publication “SynchroFine 205 HS” by PRÄWEMA Antriebstechnik GmbH, Eschwege/Werra, Germany.
In honing where a toothed workpiece such as a gear wheel or a gear is involved, the tooth flanks are passed in a so-called honing ring which is made usually of a ceramic material or is coated with a ceramic material. Material is removed thereby from the tooth flanks of the workpiece. The honing ring is basically annular in shape and comprises, for its part, radially inwardly directed tooth flanks.
As the workpiece and honing ring are being passed back and forth, the honing ring is rotated by means of a tool spindle. Likewise, the workpiece is rotated by means of a workpiece spindle. In this, the workpiece spindle rotates at speeds up to the order of 10,000 rpm. Since, in honing, the excess material removed is only in the order of 15-50 μm, the honing ring and the workpiece have to be aligned and synchronized very precisely with each other. Accordingly, the honing ring must be held firmly and positioned accurately in the tool spindle.
In the prior art, a hydraulically-centering system is used for this. In order to hold the honing ring for the processing operation, hydraulic expansion elements for the honing ring are clamped in the radial direction as a hydraulic medium (usually a hydraulic oil) is forced into the expansion elements. The expansion elements prevent the honing ring from moving radially.
In the prior art, such as in the “SynchroFine 205 HS” mentioned above, the pressure in the hydraulic system is applied by a plurality of screws. In a tool change (exchange of honing ring), possibly the result of wear or a changeover to another type of workpiece, these screws must all be loosened and re-tightened, making the tool change quite time-consuming.
The object of the invention is to provide a tool spindle for a honing machine whereby a tool change can be done faster and more easily. The present invention fulfills these needs and provides other related advantages.